Session: 15-01-01: ASME International Undergraduate Research and Design Exposition

Paper Number: 100660

100660 - A Novel Magnetorheological Elastomer-Based Artificial Pancreas 

Automated Insulin Delivery (AID) systems, also known as Hybrid Closed Loop (HCL) systems or Artificial pancreas (AP) systems are used to monitor and control blood glucose levels, which would otherwise have serious health problems for diabetic patients, including damage to the heart, kidneys, eyes, and nerves. Today there are 1.6 million Americans are living with Type 1 Diabetes (T1D), including about 200,000 youth (less than 20 years old) and 1.4 million adults (20 years old and older). Despite the demonstrated clinical benefits, T1D patients avoid taking advantage of such AP systems because of the burden of wearing an on-body insulin pump. Also, the patients need to wear two different devices separately, i.e., (i) a continuous glucose monitoring system and (ii) an insulin pump, which only contributes to the physical and psychological burdens on the patients. Thus, there is a pressing need for insulin delivery systems with reduced “form-factors” and other “user-centric” features to increase the greater adoption of such devices in the T1D community. To offer a potential solution, we propose a novel magnetorheological peristaltic micropump (MR-µPUMP) that has not been studied previously to offer an efficient, miniature (on the order of 1 mm), lightweight, portable, wirelessly controllable (with a fast response time of less than 100 ms), durable, low power micropump for insulin delivery. The MR-µPUMP relies on an electromagnetic actuation mechanism. The pump chamber is made of a smart material called magnetorheological elastomer (MRE). The MRE is consisting of a rubber-like base material and micron-sized iron particles doped in it. Under a magnetic field, the chamber contracts, and the amount of contraction depends on the intensity of the applied magnetic field, which can be controlled via electromagnets. A series of electromagnets actuate the chamber sequentially to generate a peristaltic motion to push the fluid forward, while one-way flow valves at each section prevent the fluid from leaking backward during the sequential contractions. This is a similar phenomenon as in the case of the peristaltic movement of a bolus of food in the esophagus except that in the micropump the actuation is achieved by magnetic stimulation. The whole MR-µPUMP system, including the flow chamber, flow sensors, drug reservoir, electromagnets, microcontroller, and mini power source to supply currents to the electromagnets can be installed on a wearable patch. As a finished product, the MR-µPUMP can be programmed and activated by using a mobile application to deliver the required insulin levels for basal and bolus doses. In this study, we carried out physics-based computer simulations in COMSOL Multiphysics software. The proposed micropump can transfer 1.9 µL of fluid in one pumping cycle, which is almost two times the other micropump models. Also, the proposed flap valve can reduce the backflow up to 10 times during the expansion phase in comparison with the no valve model. The parametric studies demonstrated that the net pumped volume of the fluid is directly proportional to the channel height and valve spacing distance and is inversely proportional to the upper wall thickness, the elastic modulus of the pump structure, width, height, and Poisson ratio of the valves. The application of the proposed micropump is not limited to the insulin delivery systems for T1D patients and can also potentially be used in a wide range of other applications such as artificial organs to transport blood, organ-on-chip applications, micro-cooling devices, and so on.

Presenting Author: Valesia Davis Georgia Southern University

Presenting Author Biography: Valesia Davis is an Undergraduate Research Assistant working on a couple of projects with Dr. Sevki Cesmeci, including the HPLC pump systems and novel magnetorheological micropump designs. Valesia has been very active in research. She was selected to participate in the McNair summer research program in Summer 2022 and worked under the supervision of Dr. Cesmeci. Valesia is set to graduate in Spring 2023 and plans to pursue an MS and/or a Ph.D. degree after graduation.

Authors:

Valesia Davis Georgia Southern University
Rubayet Hassan Georgia Southern University
Mohammad Fuad Hassan Georgia Southern University
Sevki Cesmeci Georgia Southern University